From the Guidelines
High IL-2 levels are significant and can indicate immune system activation, potential inflammatory processes, and increased risk of atrial fibrillation, particularly in cancer patients receiving immunotherapy, as reported in a 2024 study 1.
Significance of High IL-2 Levels
High IL-2 levels can suggest autoimmune disorders, active infection, or therapeutic effects in cancer patients. However, excessive IL-2 can cause capillary leak syndrome, and monitoring IL-2 levels is crucial to assess disease activity and potential complications.
Clinical Implications
- Elevated IL-2 levels may be associated with atrial fibrillation, as seen in patients with metastatic renal cell cancer treated with high-dose IL-2 and interferon alpha 1.
- IL-2 administration can cause hypotension, and blood pressure targets should be based on baseline blood pressure, with intravenous fluid boluses or pressors used as needed 1.
- The abbreviated course of high-dose IL-2 used for tumor-infiltrating lymphocyte cell therapy can cause fewer side effects than therapeutic IL-2, but still requires careful monitoring and management of potential complications 1.
Management Strategies
- Clinicians should interpret elevated IL-2 in context with other clinical findings and laboratory values to determine appropriate management strategies.
- Monitoring IL-2 levels can help assess disease activity, treatment response, and potential complications in various conditions.
- Supportive therapy, including antihypertensive medications, acetaminophen, and antiemetics, may be necessary to manage side effects associated with IL-2 administration 1.
From the Research
Significance of High IL-2 Levels
- High IL-2 levels have been associated with both positive and negative effects on the immune system 2, 3.
- IL-2 is essential for maintaining functional regulatory T cells (Treg) and controlling immune responses, which can help prevent autoimmune diseases 2, 4.
- However, high IL-2 levels can also promote autoimmune responses and inflammation, highlighting the complex role of IL-2 in immune regulation 3, 4.
- The mechanisms by which IL-2 regulates CD4+ T cell differentiation and function have been elucidated, and IL-2 also regulates the effector and memory responses of CD8+ T cells 3.
- High IL-2 levels can have therapeutic potential in the treatment of autoimmune diseases and cancer, particularly through the use of IL-2 complexes or engineered IL-2 biologics 2, 3, 5.
IL-2 and Autoimmunity
- IL-2 has been shown to play a unique role in the development of autoimmune responses, with both IL-2-dependent and IL-2-independent mechanisms operating at specific stages of the inflammation process 4.
- The interplay between Treg, IL-2, autoimmune response, and adaptive immunity is complex, and IL-2 can have both preventive and promotional effects on autoimmunity 4.
- High IL-2 levels can contribute to the development of autoimmune diseases, but IL-2 is also required for the generation and maintenance of regulatory T cells that provide lifelong protection from autoimmune disease 4.
IL-2 and Cancer
- IL-2 has been used as a therapeutic strategy in cancer treatment, particularly in immunotherapy 3, 5.
- Engineered IL-2 biologics have shown promise in preclinical studies and clinical trials, targeting Treg cells to counteract the dysregulated immune system in autoimmunity and inflammatory disorders or targeting effector T cells, memory T cells, and natural killer cells to enhance their antitumor responses 5.
- High IL-2 levels can enhance the antitumor responses of CD8+ T cells and memory T cells, making IL-2 a potential therapeutic target in cancer treatment 3, 5.